Use the matching PT-SINGLE or PT-DUAL manual when replacing a supplied thermistor with a supported RTD sensor.
The PT-SINGLE and PT-DUAL / GPT-230 manuals support a supplied thermistor or a three-wire RTD sensor. An RTD must match the controller’s specified sensor characteristics; do not assume any two-, three-, or four-wire sensor is interchangeable.
- Identify the exact controller and sensor. Disconnect power before changing sensor wiring or internal switches.
- Follow Figure 5 in that controller’s manual for the RTD terminals and any required DIP-switch configuration. The PT-SINGLE and PT-DUAL diagrams must not be interchanged.
- Select the corresponding sensor type in the controller’s Sensor Type setting. Wiring alone does not complete configuration.
- Verify the displayed temperature and the intended operating and alarm settings before returning the system to service.
The supplied thermistor is specified for −40°F to 230°F (−40°C to 110°C). A wider controller display or RTD range does not establish that the connected heater, cable, pipe, or complete application is rated for those temperatures. Have the qualified installer verify the ratings of the complete system.
Sources
- Manufacturer instructions (publication 8740), PDF pp. 4–6, including Figure 5.
- Manufacturer instructions (publication 8741), PDF pp. 5–7 and 12, including Figure 5.
